When an app's LOCAL_SDK_VERSION is lower than the support library's
LOCAL_SDK_VERSION, we artifically raises the "SDK version" "linked"
by ProGuard, to
- suppress ProGuard warnings of referencing symbols unknown to the
lower SDK version.
- prevent ProGuard stripping subclass in the support library that
extends class added in the higher SDK version.
This allows us to remove the dangerous ProGuard flag
"-dontwarn android.support.**".
Notes:
- We don't raise the app's LOCAL_SDK_VERSION, so that the app's own
code is still unable to use the higher SDK version.
- For platform build, we can't just raise to the "current" SDK,
because would break apps that use APIs removed from the current SDK.
We raise it to framework.jar instead, which contains the most complete
symbol set.
Bug: 20658265
Change-Id: I90099073457a65cb8031fbaec6b396d68ce614a7
(cherry picked from commit 8e8d1e7aba)
It seems with that flag Proguard modifies the class files in a way that
Dalvik does not like.
Bug: 10307364
Change-Id: If0cc7552da00ae8a3a3a39a9f2f029819ca3164a
So all most commonly-used flags go to proguard_basic_keeps.flags
and they will still be applied when LOCAL_PROGUARD_ENABLED=nosystem.
Bug: 9203442
Change-Id: If018076dc625ac1efe31898b179dbba850218aaf